1. Field of the Invention
The present invention relates to a secondary battery.
2. Description of the Related Art
A lithium ion secondary battery includes a core pack having a bare cell and a protection circuit module.
The bare cell includes a positive electrode plate, a negative electrode plate, an electrolyte, and a separator to supply power to an external electronic device. The bare cell is capable of repeated charging and discharging operations during use. The protection circuit module protects the secondary battery from overcharge and overcurrent and prevents lowering of performance due to overdischarge.
The protection circuit module is located on the top of the bare cell and is coupled to the bare cell by a lead plate. It is one of the important issues to increase the coupling strength between devices while increasing the volume energy density of the entire package when the protection circuit module, the bare cell, and the lead plate are coupled to each other.